Wicky Tse sent in the following photograph of a sign in the Xujiahui district of Shanghai:
The topmost wording reads:
Xújiāhuì pàichūsuǒ 徐家汇派出所
("Xujiahui local police station")
Next comes five big characters and a large comma:
huāqián yuèxià shí 花前月下時,
("when [you're] in front of the flowers and beneath the moon,")
That is followed by this warning:
qǐng zhùyì nǐ de kuàbāo 请注意你的挎包
("please pay attention to your purse / shoulder bag")
Probably every native speaker of English who reads the first English clause ("When you are getting off with your lover") will do a double-take. If they could read the equivalent Chinese, they would be even more dumbfounded.
The expression "huāqián yuèxià" 花前月下 ("in front of the flowers and beneath the moon") derives from a heptasyllabic quatrain entitled " Lǎo bìng" 老病 ("Old and Ill") by the famous Tang poet Bo Juyi 白居易 (772-846), the first two lines of which read:
Zhòu tīng shēnggē yè zuì mián, ruòfēi yuè xià jí huā qián
By day listening to music and song, by night in a drunken sleep;
If not beneath the moon, then in front of the flowers.
Abbreviated as "huāqián yuèxià" 花前月下 ("in front of the flowers and beneath the moon"), this line has become a chéngyǔ 成語 ("set phrase" [often rendered as "idiom" or "proverb"]) indicating an ideal setting for a couple in love.
"Huāqián yuèxià" 花前月下 ("in front of the flowers and beneath the moon") is not the only Chinese expression that yields the Chinglish translation "getting off". Witness this road sign (from China-Mike.com):
The sign actually says:
zhǐ zhǔn línshí tíngchē xiàkè 只准臨時停車下客
Temporary stopping only to unload passengers.